Answer :
It would be the journal written by Christopher Columbus. (even though he didn't actually discover the new world, so he shouldn't get credit for it... but that's how it's taught in history.)
The answer would be: C. A journal written by Christopher Columbus on one of his voyages!
This is because a primary source, is an artifact, book, article, etc. that was created at the time of a study or case. In this problem it was a journal that was written by Christopher Columbus, in his time! All of the other information was written after, and was information that had been researched!
I hope this helps some of you guys! Thanks